Evidence Quality Assessment of Tai Chi Exercise Intervention in Cognitive Impairment: An Overview of Systematic Review and Meta-Analysis

Table 6

Results of evidence quality.

Author, year (country)	Outcomes	Studies (participants)	Limitations	Inconsistency	Indirectness	Imprecision	Publication bias	Relative effect (95% CI)	Heterogeneity (%)	Quality
Liu et al., 2021 (China) [27]	MoCA (global cognitive function)	5 (344)	0 (1)	−1 (2)	0	−1 (3)	−1 (4)	WMD = 3.23, 95% CI (1.88, 4.58)	I2 = 92	Very low
	MMSE (global cognitive function)	3 (187)	0	−1 (2)	0	−1 (3)	−1 (4)	WMD = 3.69, 95% CI (0.31, 7.08)	I2 = 83	Very low
	TMT-B (executive function)	2 (147)	0	0	0	−1 (3)	−1 (4)	WMD = −13.69, 95% CI (−21.64, −5.74)	I2 = 0	Low
Yang et al., 2020 (China) [28]	Global cognitive function	5 (858)	0	−1 (2)	0	0	−1 (4)	SMD = 0.40, 95% CI (0.24, 0.55)	I2 = 63	Low
	Memory and learning	7 (855)	0	−1 (2)	0	0	−1 (4)	SMD = 0.37, 95% CI (0.24, 0.51)	I2 = 67	Low
	Mental speed and attention	6 (929)	0	−1 (2)	0	0	−1 (4)	SMD = 0.51, 95% CI (0.31, 0.71)	I2 = 84	Low
	Ideas, abstraction, figural creations, and mental flexibility	6 (782)	0	0	0	0	−1 (4)	SMD = 0.29, 95% CI (0.16, 0.42)	I2 = 0	Moderate
	Visuospatial ability	3 (192)	0	0	0	−1 (3)	−1 (4)	SMD = 0.29, 95% CI (0.10, 0.48)	I2 = 0	Low
Gu et al., 2021 (China) [29]	MMSE (global cognitive function)	6 (673)	−1 (1)	−1 (2)	0	0	−1 (4)	WMD = 1.52, 95% CI (0.90, 2.14)	I2 = 63	Very low
	MoCA (global cognitive function)	3 (244)	−1 (1)	−1 (2)	0	−1 (3)	−1 (4)	WMD = 3.5, 95% CI (0.76, 6.24)	I2 = 92	Very low
	CDR (global cognitive function)	2 (285)	−1 (1)	0	0	−1 (3)	−1 (4)	WMD = −0.55, 95% CI (−0.80, −0.29)	I2 = 0	Very low
	LMD (memory and learning)	3 (435)	−1 (1)	−1 (2)	0	0	−1 (4)	WMD = 1.10, 95% CI (0.04, 2.16)	I2 = 77	Very low
	DSF (executive function)	2 (287)	−1 (1)	−1 (2)	0	−1 (3)	−1 (4)	WMD = 0.53, 95% CI (−0.65, 1.71)	I2 = 64	Very low
	DSB (executive function)	2 (287)	−1 (1)	0	0	−1 (3)	−1 (4)	WMD = −0.1, 95% CI (−0.38, 0.19)	I2 = 0	Very low
Lin et al., 2021 (China) [30]	Global cognitive function	2 (272)	0	0	0	0	−1 (4)	WMD = -2.24, 95% CI (−3.51, −0.97)	I2 = 0	Moderate
	Memory and learning	3 (126)	0	−1 (2)	0	−1 (3)	−1 (4)	SMD = 0.83, 95% CI (0.22, 1.45)	I2 = 57	Very low
	Visuospatial ability	2 (85)	0	0	0	−1 (3)	−1 (4)	WMD = 3.15, 95% CI (0.74, 5.56)	I2 = 0	Low
	Executive function	3 (376)	0	0	0	−1 (3)	−1 (4)	WMD = 0.32, 95% CI (0.03, 0.61)	I2 = 0	Low
	Physical activity	2 (53)	0	0	0	−1 (3)	−1 (4)	WMD = 18.78, 95% CI (10.80, 26.76)	I2 = 0	Low
	Psychological assessment	2 (272)	0	0	0	−1 (3)	−1 (4)	WMD = 0.17, 95% CI (−0.62, 0.96)	I2 = 0	Low
Cai et al., 2020 (China) [31]	Global cognitive function	12 (1,738)	0	−1 (2)	0	0	0	SMD = 0.41, 95% CI (0.33, 0.48)	I2 = 67	Moderate
	Memory function	16 (1,708)	0	−1 (2)	0	0	0	SMD = 0.31, 95% CI (0.22, 0.39)	I2 = 69	Moderate
	Executive function	9 (1,586)	0	−1 (2)	0	0	0	SMD = 0.33, 95% CI (0.25, 0.42)	I2 = 77	Moderate
	Verbal fluency	5 (1,325)	0	0	0	0	0	SMD = 0.27, 95% CI (0.13, 0.41)	I2 = 0	High
	Attention	6 (1,479)	0	−1 (2)	0	0	0	SMD = 0.25, 95% CI (0.17, 0.34)	I2 = 96	Moderate
	Visual space function	3 (192)	0	−1 (2)	0	−1 (3)	0	SMD = 0.03, 95% CI (−0.28, 0.33)	I2 = 55	Low
Li et al., 2021 (China) [32]	GDS (psychological assessment)	2 (110)	−1 (1)	0	0	−1 (3)	−1 (4)	WMD ＝ −2.81, 95% CI (−3.48, −2.14)	I2 = 45	Very low
	DSF (executive function)	2 (355)	0	−1 (2)	0	−1 (3)	−1 (4)	WMD = 1.22, 95% CI (−0.68, 3.12)	I2 = 82	Very low
	DSB (executive function)	3 (620)	0	0	0	−1 (3)	−1 (4)	WMD = 0.17, 95% CI (−0.03, 0.36)	I2 = 18	Low
	MoCA (global cognitive function)	2 (136)	−1 (1)	−1 (2)	0	−1 (3)	−1 (4)	WMD = -1.58, 95% CI (−9.79, 6.64)	I2 = 97	Very low
	AVLT (memory and learning)	2 (123)	−1 (1)	−1 (2)	0	−1 (3)	−1 (4)	WMD ＝ 1.27，95% CI (0.31, 2.23)	I2 = 51	Very low
	LMD (memory and learning)	3 (660)	0	−1 (4)	0	0	−1 (4)	WMD ＝ 2.26, 95% CI (0.35, 4.16)	I2 = 93	Low
	MMSE (global cognitive function)	4 (704)	0	0	0	0	−1 (4)	WMD = 0.93, 95% CI (0.40, 1.47)	I2 = 0	Moderate
Zhang et al., 2017 (China) [33]	Global cognitive function	3 (678)	−1 (1)	0	0	0	−1 (4)	WMD = 0.91, 95% CI (0.37, 1.46)	I2 = 0	Low
	Verbal fluency	2 (654)	−1 (1)	0	0	0	−1 (4)	WMD = 2.17, 95% CI (0.88, 3.45)	I2 = 0	Low
	Memory function	2 (654)	−1 (1)	−1 (2)	0	−1 (3)	−1 (4)	WMD = 0.16, 95% CI (−0.14, 0.45)	I2 = 55	Very low
Zhang et al., 2020 (China) [34]	Global cognitive function	5 (785)	0	0	0	−1 (3)	−1 (4)	WMD = 0.29, 95% CI (−0.16, 0.74)	I2 = 0	Low
	Memory function	4 (726)	0	0	0	0	−1 (4)	WMD = 0.37, 95% CI (0.13, 0.61)	I2 = 7	Moderate
	Executive function	4 (726)	0	0	0	−1 (3)	−1 (4)	WMD = 0.03, 95% CI (−0.16, 0.22)	I2 = 0	Low
	Verbal fluency	2 (594)	0	0	0	−1 (3)	−1 (4)	WMD = 0.47, 95% CI (−0.76, 1.70)	I2 = 0	Low
	Visual space function	4 (726)	0	−1 (2)	0	0	−1 (4)	SMD = 0.57, 95% CI (0.23, 0.91)	I2 = 75	Low
	Psychological assessment	4 (730)	0	0	0	−1 (3)	−1 (4)	SMD = 0.00, 95% CI (−0.14, 0.15)	I2 = 0	Low

Note. (1) The included studies had a large bias in methodology such as randomization, allocation concealment, and blinding. (2) The confidence interval overlapped less or the I2 value of the combined results was larger. (3) The sample size from the included studies did not meet the optimal sample size or the 95% confidence interval crossed the invalid line. (4) The funnel chart was asymmetry. The 95% confidence interval did not cross the invalid line. MoCA, Montreal Cognitive Assessment Scale; MMSE, mini-mental state examination; TMT-B, trail marking test B; CDR, clinical dementia rating; DSF, digit span forward; DSB, digit span backward; LMD, Logical Memory Delayed Recall Score; GDS, Geriatric Depression Scale; AVLT, auditory verbal learning test.